At first glance, it may seem like just a black truck filled with bottles of water, but a closer look reveals a darker — or rather murkier — side to what's sloshing around inside.

Its cargo of more than 500 bottles of Nongfu Spring, a ubiquitous Chinese brand, filled with contaminated water from the village of Xiaohaotu in China's Shaanxi province is being driven around Beijing as a reminder of the costs of the country's rapid economic development.